Telephone-relay.



.No. 799,554. PATENTED SEPT. 12, 1905.

B. GATI.

TELEPHONE RELAY.

APPLICATION FILED FEB. 9,1904.

, Fig.4: A

UNITED STATES PATE NT OFFICE.

TELEPHONE-RELAY.

Specification of Letters Patent.

Patented Sept. 12, 1905.

Application filed February 9, 1904:. Serial No. 192 ,814.

To all whom, it may concern:

Be it known that I, BiiLA GATI, residing at Budapest, in the Kingdom of Austria-Hungary, have invented certain new and useful Improvements in Telephone-Relays, of which the following is a specification.

The relaying of telephonic currents has hitherto been effected mainly by means of mechanical devices, which, however, were very complicated and could only be applied with considerable difficulty.

According to the present invention such relaying is effected entirely by electrical means, for which purpose a non-metallic resistance is suitably combined in a local circuit with the source of continuous current and the two linewires, which carry the original and relayed currents, respectively, are connected with transformers which are arranged to influence and to be influenced by the currents flowing in the local circuit.

As metallic resistances are. designated, generally speaking, such resistancesthat increase in amount when the strength of the current passing through them increases. In this connection the term resistance not only includes the ohmic resistance, but also every other kind of resistance that occurs with continuous and telephone currents. If with a metallic resistance the current is increased by any meanssuch, for instance, as by superpositionthe metal becomes correspondingly heated, and as, generally speaking, the conducting power of the metal decreases with an increase of temperature the resistance is'correspondingly increased, and consequently under certain circumstances the current passing through a metallic resistance cannot exceed a certain limit. On the other hand, with the non-metallic resistances employed according to this invention (as a type of which may be taken the well-known Nernst incandescence body) I the resistance decreases with an increase in the strength of the current. If therefore the current is supplied from a source the voltage of which is maintained constant, the strength of current in the circuit supplied will increase in consequence of the decrease of the resistance. This increase of current causes a further decrease of resistance, and consequently a further increase of the current, and so on until the incandescence body is consumed in consequence of the excessive strength of current. In order to prevent this, a metallic resistance is employed in. combination with the N ernst incandescence body.

In the accompanying drawings, Figures 1 and 2 illustrate, by way of example, curves showing the relation between the resistance R and the strength of current J with the Nernst incandescence body or with an electric arc of five millimeters length produced between carbon electrodes. Generally speaking, this relation always exists whenever gas is contained between the electrodes. Thus it also occurs with the ordinary electric incandescent lamps in which the attenuated conducting gas body is included in parallel with the filament. The phenomenon also occurs with vacuum-tubes, and its cause may be attributed to the ionization of the gas.

Fig. 3 shows the simplest possible arrangement of a telephone-relay utilizing the principles above explained. This arrangement is substantially that described in the specification of my former patent, No. 684,506, October 15, 1901. In the arrangement of Fig. 3 there is included in the circuit comprising the windings of two transformers the body A, whose resistance decreases when the strength of the current passing through the same increases. As the current induced in the local circuit by the telephone current passing through the transformer in line-wire I com bines with the current flowing through said local circuit, the strength of the latter current increases, while the resistance of the body A decreases in a corresponding manner. In consequence of such decrease of resistance the current strength still further increases, and so on, the result of which will be that a current will be induced through the transformer in line-wire II that is stronger than that coming from I.

In order to avoid the action of the electrolyte upon the telephonic current, the relay is constructed in practice according to this invention in the manner shown in Figs. 4 and 5, in which there are included coils S between the continuous-current source and the body A, while between the transformer-windings and the body A there are included condensers. The arrangement can of course be variously modified according as the relay resistance consists of a Nernst incandescence body, a carbon arc-light, a mercury arc-light, a glowlamp, a vacuum-tube, a carbon contact, or the like. The proportions of the transformers and the condensers depend, of course, upon the conditions of intensity and pressure,the phaseshift, &c., and require to be specially determined for each particular case. In general,

I magnetic field.

'relay resistance employed.

it is of advantage that the diameter of the coils S employed with the current source should be made as small as possiblethat is to say, that long coils of comparatively thick wire having a comparatively small ohmic resistance should be employed. In order to render the action still more reliable, the magnetic action of the telephonic current may also be utilized. As above stated, the ionized gas in the relay resistance has to be taken into account. If in consequence of the influence of a magnetic field even only a portion of the drop of potential in the gas between the electrodes is subject to a variation, the drop of potential itself will be varied and with it the strength of the current. As, furthermore, the magnetic field operates in a different manner in the separate portions of the gas in consequence of the differences in the form of the current in the gas pressure, in the temperature, &c., the total action will also be different. If, for instance, with a vacuum-tu be the transverse magnetic field operates on the cathode, the drop of potential decreases and the intensity of the current in general increases with the increase of the If, however, the magnetic field acts not only upon the cathode, but also upon the entire body of the gas when this is at atmospheric pressure, the drop of potential will increase, while the intensity of the current will decrease with the increase of the magnetic field. The variations are often contradictory and cannot be determined beforehand. The suitable position of the several parts can therefore only be determined experimentally, according to the nature of the In general the arrangement is easier with a magnetic field at right angles to the current flowing through the relay resistance.

The arrangement may for practical purposes be advantageously that shown in Fi 6, where the magnetic field of the transformers themselves is utilized for the above purpose. The poles B U of the transformer-magnets can be variously formed. The magnetic field can be made to act in annular form upon the relay-resistance or in the manner shown in Fig. 6. The precise arrangement for obtaining the most advantageous action of the transformers must also in this case be determined experimentally, and with the explanations above given this will be within the power of any competent telephone engineer.

What I claim is 1. The combination of an electric circuit including a source of current and a non-metallic resistance the resistance of which decreases with increase of current flowing through the same, a second circuit, condensers in said second circuit connected also to the first circuit, a source of potential variation adapted to act inductively on the second circuit, and a re ceiving apparatus for the electrical variations in the second circuit resulting from the variations in the first circuit.

2. The combination of an electric circuit including 'a source of current, a non-metallic resistance the resistance of which decreases with increase of current flowing through the same, and coils between the current source and the terminals of the non-metallic resistance, a second circuit, condensers in said second circuit connected also to the first circuit, a source of potential variation adapted to act inductively on the second circuit, and a receiving apparatus for the electrical variations in the second circuit resulting from the variations in the first circuit.

3. The combination of an electric circuit including a source of current and a non-metallic resistance the resistance of which decreases with increase of current flowing through the same, a second circuit, condensers in said second circuit connected also to the first circuit, two induction-coils,one winding of each of which is included in the second circuit, and receiving and transmitting line-wires connected to the other windings of the respective induction-coils.

4. The combination of an electric circuit including a source of current, a non-metallic resistance the resistance of which decreases with increase of current flowing through the same, and coils between the current source and the terminals of the non-metallic resistance, a second circuit, condensers in said second circuit connected also to the first circuit, two induction-coils one winding of each of which is included in the second circuit, and receiving and transmitting line-wires connected to the other windings of the respective induction-coils.

5. The combination of an electric circuit including a source of current and a non-metallic resistance the resistance of which decreases with increase of current flowing through the same, a second circuit, condensers in said second circuit connected also to the first circuit, two induction-coils one winding of each of which is included in the second circuit, cores adapted to be influenced magnetically by said induction-coils and to act magnetically upon the non-metallic resistance, and receiving and transmittingline-wires connected to the other windings of the respective induction-coils.

6. The combination of an electric circuit including a source of current, a non-metallic resistance the resistance of which decreases with increase o1 current flowing through the same, and coils between the current source and the terminals of the non-metallic resistance, a second circuit. condensers in said second circuit connected also to the first circuit, two induction-coils one winding of each of which is included in the second circuit, cores adapted to beinfluenced magnetically bysaid inductioncoils and to act magnetically upon the nonmetallic resistance, and receiving and trans- ITO mitting linewires connected to the other windings of the respective induction-coils.

'7. In combination, a source of current,a non-metallic resistance such thatits resistance decreases with increase in the current flowing through it, a circuit including the current source and the non-metallic resistance, a second circuit containing two condensers and one of the windings of each of two inductioncoils, said second circuit so arranged as to be bridged by the non-inductive resistance in the first circuit, cores adapted to be influenced magnetically by the induction-coils and to act magnetically upon the non-metallic resistance, and line-wires connected to the other windings of the induction-coils.

8. in combination, a source of current, a non-metallic resistance such that its resistance decreases with increase in the current flowing through it, conducting electrical connections including coils connected between the terminals of the current source and of'the non-metallic resistance, a circuit containing two condensers and one of the windings of each of two induction-coils, said circuit so ar- BELA GATI.

Witnesses:

ADOLF HALAN, JOHN GERZUTZX. 

